''Trichogenes longipinnis'' (the long-finned cambeva), is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

catfish Catfish (or catfishes; order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the three largest species alive, ...

(

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

Siluriformes) of the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Trichomycteridae Trichomycteridae is a family of catfishes commonly known as pencil catfishes or parasitic catfishes. This family includes the candiru fish (''Vandellia cirrhosa''), feared by some people for its alleged habit of entering into the urethra of hum ...

. ''T. longipinnis'' is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to coastal streams in the

Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...

forest between

Rio de Janeiro Rio de Janeiro ( , , ; literally 'River of January'), or simply Rio, is the capital of the state of the same name, Brazil's third-most populous state, and the second-most populous city in Brazil, after São Paulo. Listed by the GaWC as a b ...

and

São Paulo São Paulo (, ; Portuguese for 'Saint Paul') is the most populous city in Brazil, and is the capital of the state of São Paulo, the most populous and wealthiest Brazilian state, located in the country's Southeast Region. Listed by the GaWC a ...

States in southeastern

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

Description

The spotted colour pattern differs consistently between stream populations, indicating genetic differentiation. This fish grows to about 14 cm (5.5 in)

standard length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish m ...

(SL) in males and 10.6 cm (4.2 in) SL in females.

Ecology

This catfish dwells in pools beneath small waterfalls in steep hill streams flowing over rocky and sandy substrates. The density of these fish varies from three to 25 individuals/m². At densities of 18 to 25 individualsm², these fish aggregate in loose groups of up to 30 individuals. However, the largest ones tend to be solitary and territorial. Unlike most trichomycterids which are bottom-dwelling and nocturnal, ''T. longipinnis'' is

nekton Nekton or necton (from the ) refers to the actively swimming aquatic organisms in a body of water. The term was proposed by German biologist Ernst Haeckel to differentiate between the active swimmers in a body of water, and the passive organisms ...

ic and active both during daytime and at night, with juvenile and small adults being more active at daytime than large adults. This catfish uses visual, tactile, and chemosensory orientation to feed on bottom-dwelling aquatic and terrestrial

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

s in the water column or on the surface. Their diet includes immature aquatic insects,

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

s, adult terrestrial winged insects, whole or fragmented, and

carrion Carrion () is the decaying flesh of dead animals, including human flesh. Overview Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters (or scavengers) include crows, vultures, c ...

. These fish forage mostly by scanning the bottom, the barbels touching the substrate, but visually oriented drift feeding is also used by smaller fish. While foraging, it may bury into sand or plant debris and sift through with its gill openings and mouth. This species reproduces at the onset of rainy season. ''T. longipinnis'' is restricted to steep hill stream stretches, and is absent in streams on gently sloping terrain dominated by ''

Astyanax In Greek mythology, Astyanax (; grc, Ἀστυάναξ ''Astyánax'', "lord of the city") was the son of Hector, the crown prince of Troy, and his wife, Princess Andromache of Cilician Thebe."Astyanax". ''Oxford Classical Dictionary''. Oxford, 1 ...

characid Characidae, the characids or characins is a family of freshwater subtropical and tropical fish, belonging to the order Characiformes. The name "characins" is the historical one, but scientists today tend to prefer "characids" to reflect their st ...

s. The catfish possibly developed, or retained, its characid-like role (diurnal, nektonic, and insectivorous) in separately with this more widespread tetra.

Conservation

Due to restricted distribution, specialized habitat, and differentiated populations, the vulnerable (VU B1+2bc) status in the IUCN List is proposed. However, this species is not yet listed on the IUCN Red List.

References

{{Taxonbar, from=Q3764313 Trichomycteridae Fish of South America Fauna of Brazil Endemic fauna of Brazil Taxa named by Heraldo Antonio Britski Taxa named by Hernán Ortega Fish described in 1983